Contacts for pin terminals

ABSTRACT

An electrical spring contact made of conductive material having two jaws for receiving a cylindrical conductive terminal. The entire assembly is formed from a single flat sheet of metal and, in addition to the jaws, each contact unit includes a long tail extending away from the jaws and available for attachment to external wiring. The contact units are each inserted into a hole in an insulator sheet and are held in place by a corrugated strip which may be either an insulator or a conductor.

United States Patent [191 Madarasz et al.

[ CONTACTS FOR PIN TERMINALS [75] Inventors: Mlklos Madarasz, Harrison;

Kenneth R. Wessel, White Plains, both of N.Y.

[73] Assignee: Sealectro Corporation,

Mamaron'eck, NY.

[22] Filed: Jan. 30, 1973 [21] Appl. No.: 328,103

[52] US. Cl. 339/217 R, 339/258 R [51] Int. Cl. H01r 9/08 [58] Field of Search 339/217 R, 217 S, 221 R, 339/256 R, 258 R, 258 P, 258 F,

339/176 MP, 176 MP, 17 L,

, 339/17 LC, 278 C [56] References Cited UNITED STATES PATENTS 3,152,849 10/1964 Deakin 339/18 2,417,967 3/1947 Booe... 339/278 C 3,346,834 10/1967 Kinkaid.... 339/217 R 3,681,741 8/1972 Lichte 339/170 [451 Apr. 23, 1974 3,720,907 3/1973 Asick 339/176 MP 3,725,843 4/1973 Johnson 339/19 3,601,775 8/1971 Longenecker et a1 339/176 MP 3,697,925 10/1972 Henschen 339/17 F Primary Examiner-Robert L. Wolfe Assistant Examiner-Robert A. Hafer Attorney, Agent, or Firm-James M. l-leilman; Wm. O. Hellman; Anthony J. Casella [5 7] ABSTRACT 4 Claims, 7 Drawing Figures CONTACTS FOR 'PIN TERMINALS BACKGROUND OF THE INVENTION The spring contacts described herein are designed to be used in plug boards wherein a large number of contacts are placed in side-by-side relationship and connected at their rear ends in rows or'columns of-parallel connections. One manner of useful connections includes a first row of contacts connected to the positive terminal of a source of electric power, a second row connected to the negative terminal of the same source. Then one or a number of external circuits can be connected to the source of power by plugging terminal connectors into the contacts. Another useful means of employing the contact array is to connect resistors, inductors and capacitors between the tail ends of the contacts and use these circuit components in external circuitry. Many other uses are known for such a plug board. Prior contact springs have generally been connected across their bases which provided less resiliency and interfered with the back connecting operations. Sometimes, separate steel springs have been added but these make the contacts more bulky. The-present invention comprises a single piece of alloy material having a side connection between the jaws. This provides all the resiliency necessary and also permits the use of a long thin connecting tail formed integral with the rest of the contact.

One of the features of the invention is the use of a single sheet of conductive material to form the jaws, the resilient connecting means, and the electrical tail connector.

Another feature of the invention is an integral design by which a punch press can manufacture the entire spring contact in a progressive action die, without any manual operations.

Another feature of the invention is a design which permits complete manufacture of the contact before being detached from a base strip. In this manner a long line of contacts, or more, can be inserted into their holes in the insulator plate in a single operation. When the contacts are in place, the base strip is broken away.

SUMMARY OF THE INVENTION The invention includes a double jawed spring contact made of a single piece of conducting metal. The jaws are formed with an expanding throat to provide easy entry of a terminal pin. The two jaws are connected by an integral bridge piece which joins two side edges of the jaws. A connecting tail is added to the bridge for back connection to an external circuit or to another similar spring contact. Several parts of the contact, such as the tail and the bases of the jaws, are provided with an offset corrugation for strength.

BRIEF DESCRIPTION OF THE FIGURES FIG. 4 is an end view of the spring contact, installed in the insulator panel and'held by a locking strip. The panel and strip are shown in section.

FIG. 5 is a side view similar to FIG. 4 but showing the side of the contact piece.

FIG. 6 is a cross sectional view of the two spring members and is taken along line 66 of FIG. 5.

FIG. 7 is another cross sectional view of the spring contact device and is taken along line 7-7 of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT The spring contact is formed from a flat sheet of conductive metal and FIG. 1 shows the contact after several operations in a punching die. All the contacts are held together by an edge strip 10 which is perforated by a plurality of index holes 11 to guide the blank through the press die and insure proper alignment with the die members. As shown in FIG. 1 blanking holes 12 have been cut in the strip leaving lugs 13 to hold the spring blanks in position for further operations by the die. At this time the two portions 14, which will be bent to form the jaws, are flat and are separated by a shear line 15, an opening 16 and a connecting tail 17. Corrugations '18 are formed in the lower portions of the jaws to stiffen them and a single long corrugation 20 is formed in the contact tail 17 to make it less flexible. In order to insure reliable electrical contact, a thin strip 21 of gold or silver is deposited as indicated, either by plating or some other convenient cladding method.

The blank is next bent to form jaws 22 and then one jaw is turned over to be opposite to the other jaw, the two jaws 22 being held resiliently in the position shown in FIG. 2 by a bridge portion 23 to grip a terminal pin 19 (see FIG. 4). FIG. 3 shows a top view of the spring contact with the jaws 22 opposed to each other but making resilient contact only at their edges. A small space 24 is left at the center of the jaws to make the entry of a terminal pin easier.

A plurality of spring contacts are formed as described above and spaced along the base strip 10, being held in position by the lugs 13. This strip of contacts is then entered into a series of holes 25 formed in a flat non-conductor 26. The holes 25 are equally spaced to conform to the spacing of the spring contacts on strip 10 so that all the contacts in any row may be entered at the same time. After being seated in their holes, a retaining strip 27 may be entered at the lower side of the insulator panel 26 and through holes 16 in each spring. If the spring contacts are to be separately connected, the strip 27 will be an insulator such as Bakelite or vulcanized fiber. If the spring contacts are to be connected together, the retaining strip 27 may be a conductor. The strip may be bent into a corrugated shape as shown in FIG. 4 to increase its resiliency.

As shown in FIGS, 3, 4 and 6, the corrugations 18 are resiliently pressed against the inner surface of holes 25 so that they will not move out of alignment when in service. The length of the contact tails 17 can be made as long as desired depending upon the width of the original blanking strip.

The invention is used to assemble a large plurality of spring contacts, as many as several hundred, on a single insulator base to form a plug board for many uses in communication networks, computers, and laboratory testing equipment.

The embodiments of the invention, in which an exclusive property or privilege is claimed, are defined as follows:

1. A spring assembly of a spring contact mounted in a hole in an insulated panel, said assembly comprising:

a spring contact having:

a. two opposed jaws, said jaws each formed with a sloping surface to create an expanded throat there between;

b. a bridge connecting the two jaws at theiredge portions and biased to press the two jaws toward each other to grip a terminal pin, said bridge positioned at a distance from the sloping end surfaces and creating a transverse opening between the insulating panel and an edge of the bridge as the bridge and jaws are inserted into a hole in the panel;

0. a connecting tail formed integral with said bridge connection to an external circuit, said tail formed with a linear corrugation for strength and extending from the bridge away from said jaw; and

d. cut-away portions adjoining the lower ends of the jaws and engaging a side of the insulating panel for limiting the degree of insertion of the spring contact into the insulating panel; and an insulating retaining strip positioned in said transverse opening defined between the bridge and the lower surface of the insulating panel for holding the spring contact in position.

2. A spring contact assembly according to claim 1 wherein the entire arrangement is formed from a single piece of conductive metal.

3. A spring contact assembly according to claim 1 wherein a band of gold is deposited on the spring material prior to forming to present a gold conductive surface at the points in the jaws where a conductive pin is engaged.

4. A spring contact assembly as claimed in claim 1 wherein a plurality of spring contacts are mounted in alignment on an insulator panel and said retaining strip engages all of the holes in the spring contacts to secure them in place and to connect them together. 

1. A spring assembly of a spring contact mounted in a hole in an insulated panel, said assembly comprising: a spring contact having: a. two opposed jaws, said jaws each formed With a sloping surface to create an expanded throat there between; b. a bridge connecting the two jaws at their edge portions and biased to press the two jaws toward each other to grip a terminal pin, said bridge positioned at a distance from the sloping end surfaces and creating a transverse opening between the insulating panel and an edge of the bridge as the bridge and jaws are inserted into a hole in the panel; c. a connecting tail formed integral with said bridge connection to an external circuit, said tail formed with a linear corrugation for strength and extending from the bridge away from said jaw; and d. cut-away portions adjoining the lower ends of the jaws and engaging a side of the insulating panel for limiting the degree of insertion of the spring contact into the insulating panel; and an insulating retaining strip positioned in said transverse opening defined between the bridge and the lower surface of the insulating panel for holding the spring contact in position.
 2. A spring contact assembly according to claim 1 wherein the entire arrangement is formed from a single piece of conductive metal.
 3. A spring contact assembly according to claim 1 wherein a band of gold is deposited on the spring material prior to forming to present a gold conductive surface at the points in the jaws where a conductive pin is engaged.
 4. A spring contact assembly as claimed in claim 1 wherein a plurality of spring contacts are mounted in alignment on an insulator panel and said retaining strip engages all of the holes in the spring contacts to secure them in place and to connect them together. 